Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@src/pymax/api/chats/service.py`:
- Around line 367-377: The delete_chat method uses a truthiness check
(`last_event_time or int(time.time() * 1000)`) which incorrectly treats 0 as
falsy and replaces it with the current timestamp. Fix this by replacing the `or`
operator with an explicit `None` check using a conditional expression (ternary
operator or `if last_event_time is None else`) to allow 0 as a valid value for
the last_event_time parameter in the DeleteChatPayload instantiation.

In `@src/pymax/base.py`:
- Around line 277-279: The code closes the store via self.close() and then
attempts to call delete_session() on the already-closed store, followed by
calling store.close() again. Reorder the operations to call delete_session() on
the store before invoking self.close(), then remove the redundant await
store.close() call since self.close() already closes the store that was
captured. This ensures the session is deleted while the store is still open and
avoids mutating a closed resource.

In `@src/pymax/dispatch/router.py`:
- Line 35: Update the test type annotations in tests/app/test_app_runtime.py to
satisfy the new ClientT bound to BaseClient. Replace all instances of
Router[object] and App[object] at lines 138, 182-183, 310-311, 385, 400, and 432
with either Any (if you want to disable type checking for those tests) or a
concrete BaseClient subclass that properly implements the BaseClient interface.
This will resolve the type constraint violation introduced by the new TypeVar
bound in the router.py file.
- Around line 142-153: The on_error method in the router class accepts a scope
parameter that can be passed as a raw string (since ErrorScope subclasses str),
but the current implementation stores it as-is in the error_handlers list via
ErrorEntry. Downstream code uses identity comparison (is operator) to check
scope values, which fails for raw strings. Normalize the scope parameter by
wrapping it with ErrorScope(scope) before creating the ErrorEntry and appending
it to self.error_handlers to ensure identity checks work correctly and
LOCAL-scoped handlers are not incorrectly treated as GLOBAL.

In `@src/pymax/session/protocol.py`:
- Line 14: The `delete_all_sessions()` method should be removed from the
`StoreProtocol` interface definition in the protocol.py file. This method is not
required by the relogin path which only uses `delete_session()`, and adding it
to the protocol breaks backward compatibility with existing custom store
implementations. Keep the bulk-purge functionality as a concrete implementation
detail in specific store classes that need it, rather than as part of the
protocol contract.

---

Nitpick comments:
In `@src/pymax/api/users/payloads.py`:
- Around line 30-37: The from_contacts class method in ImportContactsPayload
currently creates a dictionary with phone as the key, which silently overwrites
earlier contact entries when duplicate phone numbers exist. Add explicit
duplicate-phone handling logic before or within the dictionary comprehension to
either reject duplicates by raising an exception, or intentionally keep the
first or last occurrence of each phone number. Make your chosen behavior clear
in the code with appropriate comments or conditional logic to prevent silent
data loss.